INSECTS: WINGS AND THEIB APPENDAGES. 71 



fly, in her swiftest flight, will in the same space of time go 

 more than the third of a mile. Now compare the immense 

 difference in size of the two animals (ten millions of the fly 

 would hardly counterpoise one racer), and how wonderful 

 will the velocity of this minute creature appear ! Did the 

 fly equal the race-horse in size, and retain its present 

 powers in the ratio of its magnitude, it would traverse the 

 globe with the rapidity of lightning.* 



Bees, again, are accomplished masters of aerial motion. 

 The Humble-bees, notwithstanding their heavy bodies, are 

 the most powerful fliers of this class. The same excellent 

 entomologist tells us that they traverse the air in segments 

 of a circle, the arc of which is alternately to right and left. 

 The rapidity of their flight is so great that could it be cal- 

 culated, it would be found, the size of the creature con- 

 sidered, far to exceed that of any bird, as has been proved 

 by the observations of a traveller in a railway carriage pro- 

 ceeding at the rate of twenty miles an hour, which was 

 accompanied, though the wind was against them, for a 

 considerable distance by a Humble-bee (Bombus subinter- 

 ruptus), not merely with the same rapidity, but even 

 greater, as it not unfrequently flew to and fro about the 

 carriage, or described zigzag lines in its flight. The 

 aerial movements of the Hive-bee are more distinct and 

 leisurely.! 



You have doubtless often admired the noble Dragon- 

 fly, with its four ample and wide-spread wings of gauze, 

 hawking in a green lane or over a pool in the noon of 

 summer. It sails, or rather shoots with arrowy fleetness 

 hither and thither, now forwards, now backwards, now to 

 the right, now to the left, without turning its body, but 

 simply by the action of its powerful and elegant wings. 

 Leeuwenhoek once saw an insect of this tribe chased by a 

 swallow in a menagerie a hundred feet long. The Dragon- 

 fly shot along with such astonishing power of wing, to the 

 * " Intr. to Entom." ; Lett. xxii. f 



